Promising new device can detect viral load in under 30 minutes

10 November 2016

Viral load testing could become more accessible to millions of people living with HIV in sub-Saharan Africa thanks to a new USB testing stick.

Getting viral load testing to millions of people in low-resource settings could now become a lot easier with the help of a new USB, which turns a droplet of blood into an electrical signal that can be read by a computer or mobile device.

Researchers from Imperial College in London and DNA Electronics developed the device, still in the early stages of development, which can measure the level of HIV in the bloodstream – known as the viral load.

Viral load is a key indicator for managing antiretroviral treatment in people living with HIV. If the viral load is high, then treatment is failing and it may be necessary to switch. Ensuring people living with HIV have regular viral load testing is important for keeping them healthy, but also for reducing the likelihood that they will develop drug resistance.

In sub-Saharan Africa, where the majority of people living with HIV reside, poor health systems and a lack of laboratories means that viral load testing is not often done – despite it being the gold standard for treatment monitoring.It is hoped that the new device could allow for people to monitor and manage their HIV status from their home, or in low-resource contexts – much like how diabetics manage their blood sugar levels.

Dr Graham Cooke, senior author of the study said, "At the moment, testing often requires costly and complex equipment that can take a couple of days to produce a result. We have taken the job done by this equipment, which is the size of a large photocopier, and shrunk it down to a USB chip.”

At the moment, the device is only a proof of concept and the authors state that further development is required before it can be used by doctors and patients.

Early results show that it is 88.8% accurate in detecting HIV levels in the bloodstream. If the device is to be used by people for monitoring their viral load, then the test sensitivity needs to increase to 95% at least – the acceptable sensitivity level indicated by the World Health Organization. Take up of the device will also depend on its cost, which at this stage is still unclear.

Professor Chris Toumazou, Executive Chairman of DNAe added: “This is a great example of how this new analysis technology has the potential to transform how patients with HIV are treated by providing a fast, accurate and portable solution.”